In the century that has passed since Frick and Lugt began to acquire works by Rembrandt, the world's view of the artist has changed dramatically. In the late nineteenth century, Rembrandt was still perceived, somewhat romantically, as an isolated and unrecognized genius who had been resistant to rules and had become increasingly withdrawn from society. Today, he is generally considered to have been an enormously ambitious artist whose extraordinary abilities and distinctive approach to making art brought him market success, international fame, and numerous students and followers during his lifetime.

Henry Clay Frick, 1905

Both the American industrialist and the Dutch scholar had their first significant encounters with Rembrandt's work in the 1890s, a decade in which the artist's celebrity reached new heights, culminating in the exhibition of 124 paintings held in 1898 in the recently built Stedelijk Museum in Amsterdam to celebrate the coronation of Queen Wilhelmina of the Netherlands. With the exception of the Self-Portrait, the other four paintings on display were each lent to the Stedelijk in 1898 as autograph works by Rembrandt; indeed, The Polish Rider, on loan from a remote castle in Galicia, was one of the sensations of this "blockbuster" exhibition.

In August 1899 Frick acquired The Portrait of a Young Artist for $38,000, his most expensive purchase to date. Then universally considered an authentic work by Rembrandt — Bernard Berenson had encouraged Isabella Stewart Gardner to buy it — this handsome portrait has long since been attributed to a follower of the artist, whose identity remains elusive. The purchase launched Frick as a collector of Old Master paintings, and over the next twenty years he would regularly be offered first refusal on the most highly esteemed Rembrandts on the market. Frick purchased selectively and was prepared to pay high sums for his Rembrandts: The Self-Portrait, 1658, entered his collection in December 1906, The Polish Rider, 1656, in April 1910, and Old Woman with a Book, c. 1655, in May 1916 (this painting is now attributed to Rembrandt's second cousin and pupil, Carel van der Pluym [1625–1672]). Frick also owned Rembrandt's pair of early portraits on panel, Portrait of a Man in a Wide-Brimmed Hat, 1633, and Portrait of a Forty-Year-Old Woman, 1634, which he acquired from the dealer Knoedler in December 1910. Within a year, he returned these pendants to the dealer and was credited their purchase price against Johannes Vermeer's Officer and Laughing Girl, which entered the collection in November 1911. These fine portraits, of unquestioned authenticity, rank today among the major Dutch paintings in the Norton Simon Art Foundation, Pasadena, and the J. B. Speed Art Museum, Louisville, respectively. Fittingly, the earlier period of Rembrandt's production as a portraitist came to be well represented at the Frick when in 1943 the Trustees purchased the portrait of the fur trader Nicolaes Ruts, signed and dated 1631 — the artist's earliest commissioned portrait, painted on a large mahogany panel. In the collection of Frick's associate J. Pierpont Morgan (1837–1913) from 1899, this was a portrait that Frick and his family must have seen on numerous occasions and known well.